Display device substrate, method for manufacturing the display device substrate, liquid-crystal device, and electronic equipment

ABSTRACT

A panel substrate includes a substrate, a plurality of display electrodes running in parallel on the substrate, and a plurality of wirings respectively continuous from the display electrodes formed on the substrate. The display electrodes and the wirings respectively have a bilayer structure of a transparent conductive layer and a metal layer. The metal layer of the display electrode is substantially narrower in width than the width of the transparent conductive layer.

BACKGROUND OF THE INVENTION

[0001] 1. Technical Field of the Invention

[0002] The present invention relates to a display device substrate foruse in a display device, a manufacturing method for manufacturing thedisplay device substrate, a liquid-crystal display device incorporatingthe display device substrate, and electronic equipment incorporating theliquid-crystal device.

[0003] 2. Description of the Related Art

[0004] Passive-matrix liquid-crystal devices include two panelsubstrates, each of which has a plurality of display electrodes runningin parallel and wirings electrically connected to the respective displayelectrodes for applying the display electrodes with voltages. The twopanel substrates are assembled to be opposed to each other in a mannersuch that the two panel substrates form a grating.

[0005] Active-matrix liquid-crystal devices having a thin-film diode(TFD) connected to each pixel are constructed by assembling a pair ofsubstrates, i.e., an element substrate, and a counter substrate, in themutually opposing position thereof. The TFDs, wirings respectivelyconnected to the TFDS, and pixel electrodes serving as displayelectrodes are arranged on the element substrate. Arranged on thecounter substrate is a plurality of display electrodes running inparallel, and wirings electrically connected to the respective displayelectrodes for applying the display electrodes with voltages. Theelement substrate and the counter substrate are assembled together insuch a manner that the pixel electrodes on the element substrate areopposed in alignment to the display electrodes on the counter substrate.

[0006] As the definition of display becomes high, and the outline areasurrounding a display area becomes narrow in these conventionalliquid-crystal devices, the wirings respectively connected to thedisplay electrodes become fine. As such a fine line design is currentlyintroduced, the resistance of the wiring increases. A drop in thevoltage applied from a drive circuit through the wiring is notnegligible.

[0007] The passive-matrix liquid-crystal devices typically employ an STN(Super Twisted Nematic) liquid crystal. The display of suchliquid-crystal display device is susceptible to a subtle variation inthe drive voltage. The wiring is electrically connected to the displayelectrode and is physically continuous from the display electrode, andis fabricated of a transparent conductive film for use as the displayelectrode, such as an ITO (Indium Tin Oxide) film. The wiring isproduced at the same time when the display electrodes are produced. As aresult, the display electrode and the wiring thereof are fabricated ofthe transparent conductive film having substantially the same filmthickness.

[0008] The wiring has a finer line width to meet compact designrequirement. To reduce resistance in the wiring, an increase in thethickness of the transparent conductive film is contemplated. However,as the thickness of the wiring increases, the time required to form thefilm lengthens. As the wiring increases in thickness, the displayelectrode, which is concurrently produced, also increases in thickness.This leads to a reduction in the transmittance ratio of the displayelectrode.

[0009] In view of the above problem, the present invention has beendeveloped. The present invention is thus designed to achieve at leastone of the three objects of reducing electrical resistance in thewiring, increasing the light transmittance ratio of the displayelectrode, and shortening the time required to form the displayelectrode and the wiring.

SUMMARY OF THE INVENTION

[0010] A display device substrate includes a plurality of displayelectrodes, and a plurality of wirings for supplying the plurality ofdisplay electrodes with a voltage, wherein the plurality of wiringsincludes a laminated structure composed of a transparent conductivelayer formed of the same layer as that of the display electrodes, and ametal layer fabricated of a metal having an electrical resistance lowerthan that of the transparent conductive layer.

[0011] Since the display device substrate thus constructed has thewirings fabricated of the laminated structure of the transparentconductive layer and the metal layer, the resistance of the wirings islow compared with the case in which the wiring is fabricated of thetransparent conductive layer only. The liquid-crystal display devicehaving the display device substrate of this invention suffers less fromimage quality degradation attributed to a voltage drop in the wirings.

[0012] Since this arrangement eliminates the need for thickening thetransparent conductive layer for the purpose of reducing the electricalresistance of the wirings, the film thickness of the transparentconductive layer in the display electrode, which is produced typicallyconcurrently with the transparent conductive layer in the wiring, is notexcessively increased. The light transmittance ratio of the displayelectrode becomes higher compared with the case in which the electricalresistance of the wirings is reduced only by thickening the transparentconductive layer.

[0013] The transparent conductive layers used in the display electrodesand the wirings become thin, compared with the case in which theelectrical resistance of the wirings is reduced only by thickening thetransparent conductive layer. The time required to form the displaydevice substrate is thus shortened.

[0014] (2) In the display device substrate discussed in paragraph (1),the display electrode may include a laminated structure composed of atransparent conductive layer, and a metal layer fabricated of a metalhaving an electrical resistance lower than that of the transparentconductive layer.

[0015] Since the display electrode has the laminated structure formed ofthe transparent conductive layer and the metal layer, the electricalresistance of the display electrode becomes lower compared with the casein which the display electrode is fabricated of the transparentconductive layer only. Since lowering the electrical resistance of thedisplay electrode does not involve increasing the thickness of thetransparent conductive layer, the light transmittance ratio of thedisplay electrode is increased.

[0016] (3) In the display device substrate discussed in paragraph (2),the metal layer in the display electrode is preferably narrower in widththan the transparent conductive layer. With this arrangement, theelectrical resistance of the display electrode is lowered with almost nodrop caused in the brightness level of the display.

[0017] (4) In the display device substrate discussed in paragraph (1) or(2), the display electrode preferably includes the laminated structureof the transparent conductive layer and the metal layer, and wherein themetal layer has an aperture partially opened in the laminated structure.

[0018] If the display device substrate of the above arrangement is usedas a rear substrate of the pair of the substrates forming theliquid-crystal device, the aperture of the display electrode permitslight to pass therethrough while the metal layer in the displayelectrode reflects light therefrom. A transflective liquid-crystaldevice thus results. Since the display electrode fabricated of thetransparent conductive layer is present in the aperture of the metallayer, electric field applied to the liquid crystal in an areacorresponding to the aperture is not disturbed.

[0019] (5) In the display device substrate discussed in paragraphs (1)through (4), the wirings may be routed from the ends of the respectivedisplay electrodes in the peripheral portion of the display devicesubstrate. Since a wiring is typically routed in a frame outline area ofa substrate, its length becomes long. The wirings, formed of thelaminated structure of the transparent conductive layer and the metallayer in this invention, are particularly advantageous in loweringwiring resistance.

[0020] (6) The liquid-crystal display device of the present inventionrelates to the one which encapsulates a liquid crystal between a pair ofsubstrates, and includes the display device substrate discussed inparagraph (1) through (5) as at least one of the pair of substrates. Inthe liquid-crystal display device thus constructed, the wirings have thelaminated structure of the transparent conductive layer and the metallayer, the electrical resistance of the wirings is rendered lower thanwhen the wirings are formed of the transparent conductive layer only.The liquid-crystal display device having the display device substrate ofthis invention suffers less from image quality degradation attributed toa voltage drop in the wirings.

[0021] Since this arrangement eliminates the need for thickening thetransparent conductive layer for the purpose of reducing the electricalresistance of the wirings, the film thickness of the transparentconductive layer in the display electrode, which is produced typicallyconcurrently with the transparent conductive layer for the wiring, isnot excessively increased. The light transmittance ratio of the displayelectrode becomes higher compared with the case in which electricalresistance of the wirings is reduced only by thickening the transparentconductive layer.

[0022] The transparent conductive layers of the display electrode andthe wirings become thinner compared with the case in which theelectrical resistance of the wirings is reduced only by thickening thetransparent conductive layer. The time required to form the displaydevice substrate is thus shortened.

[0023] (7) The liquid-crystal display device of the present invention,includes the display device substrate discussed in paragraph (4), acounter substrate opposed to the display device substrate, and aliquid-crystal layer encapsulated between the display device substrateand the counter substrate, wherein the liquid-crystal device has atransmissive-type display function using the aperture of the metal layeras a light transmissive section and a reflective-type display functionusing the region of the metal layer as a light reflective section.

[0024] Since in the liquid-crystal device thus constructed, the wiringshave the laminated structure of the transparent conductive layer and themetal layer, the electrical resistance of the wirings is rendered lowcompared with the case in which the wirings are formed of thetransparent conductive layer only. The liquid-crystal display devicehaving the display device substrate of this invention suffers less fromimage quality degradation due to a voltage drop in the wirings.

[0025] Since this arrangement eliminates the need for thickening thetransparent conductive film for the purpose of reducing the electricalresistance of the wirings, the film thickness of the transparentconductive layer in the display electrode, which is produced typicallyconcurrently with the transparent conductive layer in the wiring, is notexcessively increased. The light transmittance ratio of the displayelectrode becomes high, compared with the case in which the electricalresistance of the wirings is reduced only by thickening the transparentconductive layer.

[0026] The transparent conductive layers of the display electrode andthe wirings become thin, compared with the case in which electricalresistance of the wirings is reduced only by thickening the transparentconductive layer. The time required to form the transparent conductivelayer is thus shortened.

[0027] (8) Electronic equipment of the present invention includes theliquid-crystal device discussed in paragraph (6) or (7) as a displaymeans. The electronic equipment provides the above-discussed advantagesof the display device. Electronic equipment having display means of ahigh image quality is provided.

[0028] (9) A manufacturing method of the present invention formanufacturing the display device substrate discussed in one ofparagraphs (1) through (5), includes a transparent conductive layerfabrication step for fabricating a transparent conductive layer on thedisplay device substrate, a metal layer depositing step for depositing ametal layer on the transparent conductive layer, and an etching step forconcurrently etching the transparent conductive layer and the metallayer.

[0029] In accordance with the manufacturing method, the transparentconductive layer and the metal layer are laminated, and the laminatedstructure is then patterned by a single etching process to form awiring.

[0030] (10) A manufacturing method of the present invention formanufacturing the display device substrate discussed in one ofparagraphs (1) through (5) includes a transparent conductive layerfabrication step for fabricating a transparent conductive layer on thedisplay device substrate, a metal layer depositing step for depositing ametal layer on the transparent conductive layer, a first etching stepfor concurrently etching the transparent conductive layer and the metallayer using a first photoresist film, and a second etching step foretching the metal layer only using a second photoresist film, whereinthe second photoresist film having a predetermined pattern is created bysubjecting the first photoresist film to exposure and developmentprocesses.

[0031] In accordance with this manufacturing method, the second etchingstep uses the second photoresist film that is obtained by subjecting thefirst photoresist film, having a predetermined pattern and used in thefirst etching step, to the exposure and development processes. Throughthe second etching step, the metal layer becoming a display electrode isetched away with part thereof being left. The photoresist is thenremoved. The pattern of the display electrode and the wirings is thusformed of a portion where both the transparent conductive layer and themetal layer are laminated and a portion where the transparent conductivelayer only is present.

[0032] In accordance with the manufacturing method, the application andthen the removal of the photoresist film are respectively performed onlyone time, resulting in a pattern where the metal layer and thetransparent conductive layer are laminated. This manufacturing methodresults in a substantial decrease in manufacturing steps in comparisonto a conventional manufacturing method in which the transparentconductive layer and the metal layer are separately patterned. In theconventional manufacturing method, each of the application and removalof the photoresist twice must respectively be performed twice. Thetransparent conductive layer and the metal layer are laminated, and theresulting laminated structure is subjected to a single etching step forpatterning to produce the wiring.

[0033] (11) In a manufacturing method for manufacturing a display devicesubstrate discussed in paragraph (10), the metal layer in the displayelectrode may be etched through the second etching step so that themetal layer is left on only the edge portion of the transparentconductive layer. In accordance with this manufacturing method, thedisplay electrode having a low electrical resistance is patterned withsubstantially reduced number of steps with almost no drop involved inthe brightness level of the display.

[0034] (12) In the manufacturing method for manufacturing a displaydevice substrate discussed in paragraph (10), the metal layer in thedisplay electrode may be etched through the second etching step so thatthe metal layer has an aperture on the transparent conductive layer. Inaccordance with the manufacturing method, the display device substratehaving the advantages discussed in paragraph (4) is produced with asmaller number of manufacturing steps involved.

[0035] (13) A liquid-crystal device of the present invention includes apair of display device substrates, and a liquid crystal encapsulatedbetween the display device substrates, wherein one of the pair ofdisplay device substrates includes a plurality of pixel electrodes, anda plurality of two-terminal-type switching elements, each connected tothe respective pixel electrode, the other of the pair of display devicesubstrates includes a plurality of display electrodes arranged instripes to be opposed to the plurality of pixel electrodes, and wiringsrespectively connected to the display electrodes, the plurality ofdisplay electrodes includes a transparent conductive layer, and thewirings include a transparent conductive layer formed of the same layeras that of the display electrodes, and a metal layer fabricated of ametal having an electrical resistance lower than that of the transparentconductive layer. The two-terminal switching element here may be a TFD(Thin Film Diode).

[0036] (14) A liquid-crystal device of the present invention includes apair of display substrates, and a liquid crystal encapsulated betweenthe display device substrates, wherein one of the pair of display devicesubstrates includes a plurality of pixel electrodes, and a plurality ofthree-terminal-type switching elements, each connected to the respectivepixel electrode, the other of the pair of display device substratesincludes a plurality of display electrodes arranged in stripes to beopposed to the plurality of pixel electrodes, and wirings respectivelyconnected to the display electrodes, the plurality of display electrodesincludes a transparent conductive layer, and the wirings include atransparent conductive layer formed of the same layer as that of thedisplay electrodes, and a metal layer fabricated of a metal having anelectrical resistance lower than that of the transparent conductivelayer. The three-terminal switching element may be a TFT (Thin-FilmTransistor).

BRIEF DESCRIPTION OF THE DRAWINGS

[0037]FIG. 1 is an exploded perspective view showing one embodiment ofthe liquid-crystal device of the present invention.

[0038]FIG. 2 is an exploded cross-sectional view showing theconstruction of the liquid-crystal device of FIG. 1.

[0039]FIG. 3 is a plan view showing one of panel substrates forming theliquid-crystal device of FIG. 1.

[0040]FIG. 4 is a plan view showing the other panel substrate formingthe liquid-crystal device of FIG. 1.

[0041]FIG. 5 is a plan view showing, in enlargement, a single displayelectrode and a wiring of the panel substrate of FIG. 4.

[0042]FIG. 6(A) is a cross-sectional view showing the wiring taken alongline F-F in FIG. 5, and FIG. 6(B) is a cross-sectional view showing thedisplay electrode taken along line G-G in FIG. 5.

[0043] FIGS. 7(A)-7(E) are cross-sectional views partially showing thepanel substrate in the manufacturing process of the panel substrates.

[0044] FIGS. 8(A)-8(C) show embodiments of the electronic equipment ofthe present invention, wherein FIG. 8(A) shows a mobile telephone, FIG.8(B) shows a wristwatch, and FIG. 8(C) shows a mobile informationterminal.

[0045]FIG. 9 is a plan view showing a modification of the single displayelectrode and its associated wiring of the panel substrate shown in FIG.4.

[0046]FIG. 10 is a cross-sectional view showing the display electrodetaken along line G-G in FIG. 9.

[0047]FIG. 11 is a block diagram showing an electrical control system ofthe electronic equipment.

[0048]FIG. 12 is an exploded perspective view showing a major portion ofanother embodiment of the liquid-crystal device of the presentinvention.

[0049]FIG. 13 is a cross-sectional view showing a major portion of theliquid-crystal device in FIG. 12.

[0050]FIG. 14 is a perspective view showing a single TFD used in theliquid-crystal device of FIG. 12.

[0051]FIG. 15 is a perspective view showing the external appearance ofthe liquid-crystal device of FIG. 12.

[0052]FIG. 16 is a plan view showing one of display device substratesforming the liquid-crystal device of FIG. 12.

[0053]FIG. 17 is a circuit diagram showing a circuit arrangement of yetanother embodiment of the liquid-crystal device of the presentinvention.

[0054]FIG. 18 is a cross-sectional view showing a major portion of theliquid-crystal device of FIG. 17.

[0055]FIG. 19 is a plan view showing the external appearance of theliquid-crystal device of FIG. 17.

[0056]FIG. 20 is a drive voltage waveform diagram showing a 1H biasvoltage swing drive method as a drive method for the liquid-crystaldevice of FIG. 17.

[0057]FIG. 21 is a drive voltage waveform diagram showing a fieldpolarity reversal drive method which is a typical drive method for usein active-matrix TFT liquid-crystal devices.

[0058]FIG. 22 is a graph plotting measurement results for verifying therelationship between a shift amount of a threshold voltage and operatingtime.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0059] The preferred embodiments of the present invention arespecifically discussed, referring to the drawings.

[0060]FIG. 1 is an exploded perspective view diagrammatically showing aliquid-crystal device 10 as a display device of the present invention.FIG. 2 is a cross-sectional view diagrammatically showing theliquid-crystal device 10 of FIG. 1. As shown, the liquid-crystal device10 includes a liquid-crystal panel 14 as a display panel, and abacklight unit 40 having a light guide plate 44 arranged behind theliquid-crystal panel 14. The liquid-crystal device 10 also includes abracket member (not shown) for protecting and keeping the liquid-crystalpanel 14 and the backlight unit 40 in position.

[0061] Referring to FIG. 2, the liquid-crystal panel 14 is constructedby arranging a first panel substrate 20 and a second panel substrate 30in an opposing position. Spacers (not shown) are dispersed between thefirst panel substrate 20 and the second panel substrate 30 to keep thetwo substrates apart by a predetermined gap therebetween. The firstpanel substrate 20 is a display device substrate that is produced byforming striped display electrodes 22 on one side of a substrate 21fabricated of a transparent material such as glass or synthetic resin.

[0062] The second panel substrate 30 works as a display device substratethat is produced by forming striped display electrodes 32 on one side ofa substrate 31 fabricated of a transparent material such as glass orsynthetic resin. The display electrodes 22 of the first panel substrate20 and the display electrodes 32 of the second panel substrate 30 arearranged to be opposed to each other in a manner such that a gratingconfiguration is formed. A so-called passive-matrix liquid-crystal panelresults.

[0063] A sealing member 19 is inserted between the pair of substrates 20and 30 in the peripheral outline thereof in a substantially rectangularconfiguration when viewed from an arrow A as shown in FIG. 2. The twopanel substrates 20 and 30 are glued onto each other with the sealingmember 19. Conductive members 26 of particles are included in thesealing member 19, thereby electrically connecting wirings 36 on thesecond panel substrate 30 to wirings 24 leading to the displayelectrodes 22 on the first panel substrate 20 via the conductive members26. In this way, voltages input to terminals 39 are applied to thedisplay electrodes 22.

[0064] A liquid crystal, for example, a liquid crystal 18 of an STNtype, is introduced into the gap between the first panel substrate 20and the second panel substrate 30 and enclosed by the sealing member 19,through a liquid crystal injection port (not shown) arranged in thesealing member 19. The liquid-crystal injection port is then closed by aseal material (now shown) after a liquid-crystal injection process.

[0065] A first polarizer 16 is mounted on the external side of the firstpanel substrate 20, while the second polarizer 17 is mounted on theexternal side of the second panel substrate 30. A retardation film 12 isarranged between the first polarizer 16 and the first panel substrate20. Alternatively, a retardation film 12 may be arranged between thesecond polarizer 17 and the second panel substrate 30. It is alsoacceptable that retardation films 12 are respectively arranged externalto both the first panel substrate 20 and the second panel substrate 30.

[0066] The liquid-crystal panel 14 is provided with a plurality ofterminals 39 on an overextension 38 of the second panel substrate 30extending over from the edge of the first panel substrate 20. Connectedto the terminals 39 are terminals of wiring boards 64 shown in FIG. 1,such as flexible boards. The wiring boards 64 bear drive ICs (not shown)for driving the display electrodes 22 and 32 (see FIG. 2) on theliquid-crystal panel 14. The terminals of the wiring boards 64 connectedto the output terminals of the drive ICs are respectively connected theterminals 39 formed on the second panel substrate 30, thereby feedingdrive voltages to the display electrodes 22 and 23.

[0067] In the liquid-crystal panel 14, the liquid crystal 18 is appliedwith a voltage difference between signals supplied to each of theplurality of display electrodes 22 formed on the first panel substrate20 and supplied to each of the plurality of display electrodes 32 formedon the second panel substrate 30. The alignment of liquid-crystalmolecules is thus controlled to turn on or turn off displaying.

[0068] Alternatively, the first panel substrate 20 or the second panelsubstrate 30 may be provided with a mount area for accommodating thedrive ICs. The drive ICs are thus mounted on the first panel substrate20 or the second panel substrate 30 using the COG (Chip On Glass)technology. In this case, the signals and voltages are supplied to thedrive ICs on the panel substrate through flexible boards.

[0069] Referring to FIG. 2, the pair of panel substrates 20 and 30 areshown widely separated for clarifying the details. In practice, the pairof panels 20 and 30 are spaced by a small gap as narrow as several μm todozens of μm. Referring to FIG. 20, the first polarizer 16 and theretardation film 12 are shown separated from the first panel substrate20, and the second polarizer 17 is shown separated from the second panelsubstrate 30. In practice, however, the retardation film 12 is almost incontact with the first panel substrate 20, the second polarizer 17 isalmost in contact with the second panel substrate 30, and the firstpolarizer 16 is almost in contact with the retardation film 12. Althoughseveral striped display electrodes 22 and 23 are shown, there areemployed a large number of striped electrodes, the number of which isdependent on the resolution requirement of the matrix display inpractice.

[0070] Referring to FIG. 1, the backlight unit 40 includes a fluorescenttube 50 as a light source, the light guide plate 44, a lens sheet 42 asa light diffusing plate, a backlight support bracket 56, and a reflector60. The fluorescent tube 50 is connected to an output terminal of aninverter (not shown) through a connector assembly 51. The invertersupplies the fluorescent tube 50 with a predetermined voltage.

[0071] The light guide plate 44 is fabricated of a transparent syntheticresin, for example. The fluorescent tube 50 as a light source is placedsubstantially in contact with an end face 45 of the light guide plate44. Light from the fluorescent tube 50 enters through the end face 45into and travels the light guide plate 44, and exits from the light exitsurface of the light guide plate 44 facing the liquid-crystal panel 14.The light then illuminates the entire display area of the liquid-crystalpanel 14. The light guide plate 44 has a flat surface area substantiallycoextending with the flat surface of the liquid-crystal panel 14 exceptfor the overextension 38 of the liquid-crystal panel 14.

[0072] The light guide plate 44 is tapered from the thickest portionthereof at the fluorescent tube 50 to be gradually thinner at it goesaway in a wedge-like cross section. With the light guide plate 44configured in this way, the quantity of light radiated toward theliquid-crystal panel 14 from the light guide plate 44 is made uniform,for example, with no difference in light intensity between at a point inthe vicinity of the fluorescent tube 50 and the farthest point away fromthe fluorescent tube 50.

[0073] The lens sheet 42, arranged in front of the light guide plate 44,diffuses light emitted from the light guide plate 44, therebyilluminating the entire display area of the liquid-crystal panel 14 withuniform light. The reflector 60 surrounds the fluorescent tube 50 exceptthe side thereof facing the light guide plate 44 so that light from thefluorescent tube 50 is reflected toward the light guide plate 44.Referring to FIG. 1, the fluorescent tube 50, shown external to thereflector 60, is actually housed in the reflector 60.

[0074] The fluorescent tube 50 of the backlight unit 40 is supplied withpower from the unshown inverter. In response to a direct-current voltageof 5 V, the inverter outputs a 250 V, 100 kHz alternating-currentvoltage to the fluorescent tube 50. Instead of the fluorescent tube 50,an LED may be used as a light source. The LED may be arranged alongsidethe light guide plate 44.

[0075] The backlight support bracket 56, having a bottom portion 57,supports the backlight unit 40 from the backside thereof. The backlightsupport bracket 56 also has a plurality of guide portions 58 verticallyextending from the bottom portion 57 thereof for aligning the backlightunit 40. The guide portions 58 are respectively shaped to receive theend faces 46 and 47 of the light guide plate 44, and are in abutmentwith the end faces 46 and 47 of the light guide plate 44. In this way,the light guide plate 44 is in substantially parallel alignment with thesurface of the bottom portion 57.

[0076] Except for the side facing the fluorescent tube 50, the backlightsupport bracket 56 has the guide portions 58 that have planar surfacessubstantially in contact with the end faces 46 and 47 of the light guideplate 44. Since the guide portions 58 and the bottom portion 57 of thebacklight support bracket 56, facing the light guide plate 44, have asufficiently high light reflectance, light from the fluorescent tube 50is reflected therefrom at a high efficiency. The backlight supportbracket 56 is integrally formed with the reflector 60.

[0077]FIG. 3 is a plan view diagrammatically showing the first panelsubstrate 20 viewed from the front of the panel and seen through thedisplay electrodes 22, etc. FIG. 4 is a plan view diagrammaticallyshowing the second panel substrate 30 vied from the front. With theliquid-crystal panel 14 viewed from the display screen side as shown inFIG. 1, the second panel substrate 30 shown in FIG. 4 is laminatedbehind the first panel substrate 20 shown in FIG. 3. In the laminatedstate thereof, the overextension 38 of the second panel substrate 30outwardly overextends over from the first panel substrate 20. Thecross-sectional view of the liquid crystal shown in FIG. 2 is takenalong line S-S shown in FIG. 3 and FIG. 4.

[0078] Referring to FIG. 3, the first panel substrate 20 includes thedisplay electrodes 22 formed as a predetermined pattern on the substrate21, and the wirings 24 to which the display electrodes 22 respectivelylead. The display electrodes 22 function as scanning electrodes orsignal electrodes. The ends of the wirings 24 are formed as pads 25serving as terminals to be connected to the conductive members 26 (seeFIG. 2).

[0079] Referring to FIG. 4, the second panel substrate 30 includes thedisplay electrodes 32, the wirings 34, and the wirings 36. The pluralityof display electrodes 32 run in parallel in a predetermined pattern onthe substrate 31. The display electrodes 32 function as the others ofthe scanning electrodes and the signal electrodes. The wirings 34 arecontinuous from the respective display electrodes 32, and are routedalong the peripheral portion of the substrate 31. The wirings 34 runtoward the overextension 38 of the second panel substrate 30 and areterminated at the terminals 39 there. The overextension 38 outwardlyextends over from the opposed first panel substrate 20 in a plan view.

[0080] The ends 37 of the wirings 36 are formed in pads that serve asconnection terminals to be connected to the conductive members 26. Theconductive members 26 electrically respectively connect the pads 37 tothe pads 25 as the connection terminals at the ends of the wirings 24formed on the first panel substrate 20. The conductive members 26 areconductive particles mixed into the sealing member 19 as shown in FIG.2. The wirings 36 also extend into the overextension 38, thereby formingthe terminals 39 at the other ends thereof.

[0081] The terminals 39 are formed as parts of the wirings 34 and 36,and are electrically connected to the corresponding display electrodes22 and 32. The display electrodes 22 on the first panel substrate 20 areconnected to the corresponding terminals 39 via the wirings 24 formed onthe first panel substrate 20, the conductive members 26, and the wirings36 formed on the second panel substrate 30.

[0082] Referring to FIG. 3, the display electrodes 22 on the substrate21 are coated with an alignment layer (not shown), fabricated ofpolyimide, for example. The alignment layer is then subjected to arubbing process in a predetermined direction. Referring to FIG. 4, thedisplay electrodes 32 on the substrate 31 are coated with an alignmentlayer (not show) fabricated of polyimide, for example. The alignmentlayer is subjected to a rubbing process in a predetermined direction.

[0083]FIG. 5 is an enlarged plan view diagrammatically showing a singledisplay electrode 32 on the second panel substrate 30 and a wring 34extending continuously from the display electrode 32. FIG. 6(A) is adiagrammatical cross-sectional view of the wiring 34 taken along lineF-F in FIG. 5, and FIG. 6(B) is a diagrammatical cross-sectional view ofthe display electrode 32 taken along line G-G in FIG. 5.

[0084] Referring to FIG. 5, the hatched regions 72 of display electrode32 and the wiring 34 indicate a metal layer such as of aluminum, havinga low electrical resistance. The region 70 of the display electrode 32indicates a transparent conductive layer such as ITO (Indium Tin Oxide).

[0085] Referring to FIGS. 6(A) and 6(B), each of the wiring 34 and thedisplay electrode 32 is formed of a laminated structure of thetransparent conductive layer 70 and the metal layer 72 having anelectrical resistance lower than that of the transparent conductivelayer 70. In the display electrode 32, the transparent conductive layer70 extends to its full width, while the metal layer 72 runs along oneedge portion of the transparent conductive layer 70 and is much narrowerin width than the transparent conductive layer 70.

[0086] On the other hand, both the transparent conductive layer 70 andthe metal layer 72 are coextensive in width with the wiring 34, and havethus substantially the same width. In this way, the electricalresistance of the wiring 34 having a width thereacross substantiallynarrower than that of the display electrode 32 is made substantiallysmall. The wirings 36 formed on the second panel substrate 30, althoughnot shown, have a construction similar to that of the wiring 34 shown inFIG. 6(A). In other words, the transparent conductive layer 70 and themetal layer 72 are laminated in substantially the same width.

[0087] The wirings 24 and the display electrodes 22 formed on the firstpanel substrate 20 shown in FIG. 3, opposed to the second panelsubstrate 30 shown in FIG. 4, may have a laminated structure of thetransparent conductive layer 70 fabricated of ITO and the metal layer 72fabricated of aluminum in the same way as in the wirings 34 and thedisplay electrodes 32 shown in FIG. 5 and FIGS. 6(A) and 6(B).

[0088] In the display device substrate formed of the first panelsubstrate 20 and the second panel substrate 30 in this embodiment asdiscussed above, each of the wiring 24 shown in FIG. 3 and the wirings34 and 36 shown in FIG. 4 has the laminated structure of the transparentconductive layer 70 and the metal layer 72. Compared with the case inwhich the wirings 24, 34, and 36 are formed only by the transparentconductive layer 70 only, the electrical resistance of the wirings 24,34, and 36 is low. The liquid-crystal display device 10 employing thepanel substrates 20 and 30 in this embodiment suffers less from an imagequality degradation attributed to a voltage drop through the wirings 24,34, and 36.

[0089] Since there is no need for thickening the transparent conductivelayer 70 for the purpose of reducing the electrical resistance of thedisplay electrodes 22 and 23, the light transmittance ratio of thedisplay electrodes 22 and 23 is increased. Although the transparentconductive layer 70 has a full width in the electrodes 22 and 23, themetal layer 72 is substantially narrower than the width of thetransparent conductive layer 70. The electrical resistance of thedisplay electrodes 22 and 32 is thus reduced without any substantialdrop in the brightness level of the display caused by the presence ofthe metal layer 72.

[0090] Since the length of each wiring 24 is short in the first panelsubstrate 20 shown in FIG. 3, the wirings 24 and the display electrodes22 may be manufactured of the conductive transparent ITO layer 70 only.Because of their short lengths, the wirings 36 shown in FIG. 4 may alsobe manufactured of the conductive transparent ITO layer 70 only.

[0091] Referring to FIG. 3, the transparent conductive layer 70 formingthe display electrodes 22 is typically concurrently produced togetherwith the transparent conductive layer 70 forming the wirings 24.Referring to FIG. 4, the transparent conductive layer 70 forming thedisplay electrodes 32 is typically concurrently produced with thetransparent conductive layer 70 forming the wirings 34 and the wirings36. Because of their bilayer structure of the transparent conductivelayer 70 and the metal layer 72 in this embodiment, the wirings 24, 34,and 36 require no thin design in the transparent conductive layer 70 fora smaller electrical resistance. The transparent conductive layer 70 ofthe display electrodes 22, which is concurrently produced with thetransparent conductive layer 70 of the wirings 24, does not need toomuch thickness. The display electrodes 32, which are concurrentlyproduced with the transparent conductive layer 70 of the wirings 34 andwirings 36, do not need too much thickness. The light transmittanceratio of the display electrodes 22 shown in FIG. 3 and the displayelectrodes 32 shown in FIG. 4 can be higher compared with the case inwhich the electrical resistance of the wirings 24, 34, and 36 is reducedonly by thickening the transparent conductive layer 70.

[0092] In the liquid-crystal device substrate of this embodiment, thetransparent conductive layer 70 used in the display electrodes 22 andthe wiring 24 shown in FIG. 3 is thin, compared with the case in whichthe electrical resistance of the transparent conductive layer 70 used inthe wirings 24 shown in FIG. 3 and the wirings 34 and 36 shown in FIG. 4is reduced only by thickening the transparent conductive layer 70.Further, the transparent conductive layer 70 used in the displayelectrodes 32 and the wirings 34 and 36 shown in FIG. 4 is thinned. Forthis reason, the time required to produce the panel substrates 20 and 30is shortened accordingly.

[0093] The manufacturing method for manufacturing the first panelsubstrate 20 shown in FIG. 3 and the second panel substrate 30 shown inFIG. 4 is now discussed, referring to the embodiments.

[0094] The display electrodes and the wirings in the first panelsubstrate 20 and the second panel substrate 30, produced by laminatingthe transparent conductive layer and the metal layer, are manufacturedthrough an transparent conductive layer fabrication step, a metal layerformation step, a first photoresist film formation step, a first etchingstep, a second photoresist film formation step, and a second etchingstep.

[0095] FIGS. 7(A)-7(E) are diagrammatic cross-sectional viewsillustrating the manufacturing process of the second panel substrate 30.FIG. 7(A) illustrates the transparent conductive layer fabrication stepand the metal layer formation step, FIG. 7(B) illustrates the firstphotoresist film formation step, FIG. 7(C) illustrates the first etchingstep, FIG. 7(D) illustrates the second photoresist film formation step,and FIG. 7(E) illustrates the second etching step. FIGS. 7(A)-7(E) showthe manufacturing process of the display electrodes 32 on the leftportions thereof, and the manufacturing process of the wirings 34 on theright portion thereof. Although a single display electrode 32 and asingle wiring 34 are shown here, a number of electrodes 32 and wirings34 are employed in practice.

[0096] In the transparent conductive layer fabrication step shown inFIG. 7(A), a transparent conductive layer 70, fabricated of an ITO film,is deposited on the transparent substrate 31 fabricated of a transparentmaterial such as glass. In the metal layer formation step also shown inFIG. 7(A), the metal layer 72 fabricated of aluminum is deposited on thetransparent conductive layer 70.

[0097] In the first photoresist film formation step shown in FIG. 7(B),a photoresist film is applied on the metal layer 72, and is thensubjected to exposure and development processes. A first photoresistfilm 74, having a predetermined pattern corresponding to the displayelectrodes 32 and the wirings 34, is thus formed.

[0098] In the first etching step shown in FIG. 7(C), the transparentconductive layer 70 and the metal layer 72 are simultaneously etchedusing the first photoresist film 74, thereby forming the pattern of thedisplay electrodes 32 and the wirings 34 in a plan view.

[0099] In the second photoresist film formation step shown in FIG. 7(D),the first photoresist film 74 remaining on the metal layer 72 in theformation region of the display electrodes 32 is then subjected toexposure and development processes. A second photoresist film 76 havinga predetermined pattern is formed by removing the photoresistcorresponding to the formation area of the transparent conductive layer70. The photoresist remains in the formation area of the wirings 34during the formation of the second photoresist film 76.

[0100] In the second etching step shown in FIG. 7(E), the secondphotoresist film 76 is used to partly etch the metal layer 72corresponding to the display electrodes 32 for patterning. The secondetching step is performed at an etch rate different from that of thefirst etching step so that the metal layer 72 is partly etched with thetransparent conductive layer 70 almost unetched.

[0101] Finally, the second photoresist film 76 is removed through anashing process, for example. The wiring 34 shown in FIG. 6(A) and thedisplay electrode 32 shown in FIG. 6(B) thus result.

[0102] In accordance with the manufacturing method of the panelsubstrate of this embodiment, the second photoresist film 76 is formedby subjecting again, to the exposure and development processes, thefirst photoresist film 74 having the predetermined pattern used in thefirst etching step shown in FIG. 7(C). Using the second photoresist film76, the metal layer 72 is partly etched with the part thereof becomingthe display electrode 32 left through the second etching step shown inFIG. 7(D). The second photoresist film 76 is then removed. The displayelectrode 32 composed of the transparent conductive layer 70 and thenarrow metal layer 72 is thus obtained.

[0103] In the above-referenced steps, a cycle of application andsubsequent removal of the photoresist film performed one time onlyresult in the display electrode 32 having the narrow metal layer 72.This process thus substantially reduces the number of steps, comparedwith the case in which the transparent conductive layer 70 and the metallayer 72 are separately patterned requiring two cycles of applicationand subsequent removal steps of the photoresist.

[0104] In the manufacturing method of the panel substrate of thisembodiment, the transparent conductive layer 70 and the metal layer 72are laminated, and are patterned through one cycle of etching to producethe wiring 34.

[0105] The manufacturing method of the panel substrate of the presentinvention has been discussed in conjunction with the display electrodes32 and the wirings 34 in the second panel substrate 30. The wirings 36are also manufactured of the laminated structure of the transparentconductive layer and the metal layer at the same process steps as thatfor the wirings 34. The display electrodes 22 and the wirings 24 on thefirst panel substrate 20 shown in FIG. 3 are manufactured in the samemanufacturing method as that for the second panel substrate 30, althoughthe patterns of the display electrodes and the wirings are differentfrom those of the counter parts of the second panel substrate 30.

[0106] In this embodiment, the metal layer 72 forming the displayelectrode 32 is arranged on the edge portion of the transparentconductive layer 70 as shown in FIG. 6(B). If no problem arises in thelight transmittance ratio of the display electrodes, it is not necessaryto locate the metal layer 72 along the edge of the transparentconductive layer 70. For example, the metal layer 72 may be arrangedalong the center line of the transparent conductive layer 70.

[0107] In the first embodiment, the liquid-crystal display device isformed of the transmissive-type panel substrate, i.e., the displaydevice substrate. In contrast, a second embodiment employs a panelsubstrate having a metal layer with slits formed thereon, instead of oneof the two panel substrates, such as the second panel substrate 30. Theremaining construction of the second embodiment remains unchanged fromthat of the first embodiment. The discussion thereof is thus notrepeated. As shown, like components are identified with like referencenumerals.

[0108]FIG. 9 is a plan view diagrammatically showing a second panelsubstrate 80 used in the second embodiment, and corresponds to FIG. 5illustrating the first embodiment. FIG. 10 is a cross-sectional viewtaken along line G-G in FIG. 9, and corresponds to FIG. 6(B) inconjunction with the first embodiment. In this embodiment, the secondpanel substrate 80 replaces the second panel substrate 30 of the firstembodiment, thereby producing a transflective-type liquid-crystaldisplay device.

[0109] In the second panel substrate 80, a display electrode 82 isformed of a bilayer structure of a transparent conductive layer 70 and ametal layer 72. A plurality of slits 84 as apertures are formed in themetal layer 72. The metal layer 72 is made of a highly reflectivematerial such as aluminum, copper, silver, or gold. When the slits 84are arranged in the metal layer 72, the display electrode 82 still hasthe transparent conductive layer 70 in the slits 84. Regardless of thesize of the slits 84, an appropriate electric field is applied in theliquid crystal even in the area of the slits 84.

[0110] During a transmissive mode, the transflective-type liquid-crystaldevice allows illumination light rays to be transmitted through thesecond panel substrate 80 through the slits 84 opened in the metal layer72 from behind the second panel substrate 80 and to enter the liquidcrystal 18. During a reflective mode, the liquid-crystal device allowslight rays to transmit the first panel substrate 20, opposed to thesecond panel substrate 80, and then the liquid crystal 18, and to bereflected from the surface of the metal layer 72.

[0111] Regardless of the transmissive mode or the reflective mode inthis embodiment, a voltage is applied to the liquid crystal 18 throughthe metal layer 72 if the slits 84 are small. When large slits 84 areused, the liquid crystal 18 is driven by the transparent conductivelayer 70 in the slits 84, rather than by the metal layer 72.

[0112] The liquid-crystal device 10 having the second panel substrate 80of this embodiment suffers less from an image quality degradationattributed to a voltage drop through the wirings 34 and the displayelectrodes 82. The wirings 34 and the display electrodes 82 of a bilayerstructure of the transparent conductive layer 70 and the metal layer 72eliminates the need for thickening the transparent conductive layer 70for the purpose of a small electrical resistance of the wirings 34.There is no need for thickening too much the transparent conductivelayer 70 in the display electrode 82, which is typically producedconcurrently with the transparent conductive layer 70 of the wirings 34.The light transmittance ratio of the display electrode 82 is thusincreased.

[0113] Since the transparent conductive layer 70 is made thin in thisway, the time required to manufacture the second panel substrate 80 isshortened.

[0114] In a way similar to the manufacturing method shown in FIGS.7(A)-7(E), the display electrode 82 of this embodiment is manufacturedthrough a transparent conductive layer fabrication step, a metal layerformation step, a first photoresist film formation step, a first etchingstep, a second photoresist film formation step, and a second etchingstep. After concurrently etching the transparent conductive layer 70 andthe metal layer 72 through the first photoresist film 74, the firstphotoresist film 74 is again subjected to exposure and developmentprocesses. The second photoresist film 76 is patterned to etch the metallayer 72 to form the slits 84.

[0115] The above-referenced embodiments have been discussed inconjunction with the passive-matrix liquid-crystal display device.Alternatively, the present invention may be applied to an active-matrixliquid-crystal device using a two-terminal switching element such as aTFD. The active-matrix liquid-crystal panel is manufactured of a pair ofsubstrates, i.e., an element substrate and a counter substrate, and aTN-type liquid crystal encapsulated therebetween.

[0116] The element substrate includes a plurality of wirings arranged instripes, TFD arranged for each pixel along each wiring, and a pixelelectrode formed of a transparent conductive layer connected to the TFD.The counter substrate opposed to the element substrate includes widedisplay electrodes running in stripes and intersecting the pixelelectrodes on the element substrate in a plan view.

[0117] The element substrate and the counter substrate are assembledwith the pixel electrodes on the element substrate being opposed to thedisplay electrodes on the counter substrate. A liquid crystal isencapsulated between the two substrates. In this liquid-crystal device,one of the wiring on the element substrate and the display electrode onthe counter substrate works as a scanning electrode, and the other ofthe wiring and the display electrode works as a signal electrode.

[0118] In the active-matrix TFD liquid-crystal device thus constructed,the wirings formed on the display substrate as the counter substrate areproduced of the laminated structure of the transparent conductive layerand the metal layer in accordance with the present invention. Theliquid-crystal device thus provides the same advantages as those of thepreceding embodiments.

[0119] The active-matrix TFD liquid-crystal device is now discussed,referring to FIG. 12.

[0120]FIG. 12 shows a major portion of the active-matrix TFDliquid-crystal device employing the display device substrate of thepresent invention, particularly, several pixels of the device inenlargement. The general construction of the liquid-crystal device 1 isshown in FIG. 15. The liquid-crystal device 1, employing a TFD (ThinFilm Diode) as a two-terminal active element, is a transflective-typeliquid-crystal device that selectively uses a reflective display workingfrom natural ambient light and a transmissive display based on anilluminating device. The liquid-crystal device 1 adopts the COG (Chip OnGlass) technology which permits liquid-crystal drive ICs to be directlymounted on a substrate.

[0121] Referring to FIG. 15, the liquid-crystal device 1 is constructedby gluing a first panel substrate 2 a to a second panel substrate 2 bwith a sealing member 3 interposed therebetween. A gap, i.e., a cellgap, surrounded by the sealing member 3 between the first panelsubstrate 2 a and the second panel substrate 2 b, is filled with aliquid crystal. Liquid-crystal drive ICs 4 a and 4 b are directlymounted on the surface of an overextension 38 of the first panelsubstrate 2 a, outwardly extending over from the second panel substrate2 b. The second panel substrate 2 b is an element substrate on which theTFDs are formed. The first panel substrate 2 a is a counter substratethat is opposed to the second panel substrate 2 b.

[0122] Arranged on the second panel substrate 2 b in an enclosuresurrounded by the sealing member 3 are a plurality of pixel electrodeswhich runs in the direction of rows XX and in the direction of columnsYY in a dot matrix arrangement. Arranged on the first panel substrate 2a in an enclosure surrounded by the sealing member 3 are stripedelectrodes. The striped electrodes are opposed to the plurality of pixelelectrodes on the second panel substrate 2 b.

[0123] A portion of the liquid crystal interposed between the stripedelectrode on the first panel substrate 2 a and the pixel electrode onthe second panel substrate 2 b constitutes a single pixel. A pluralityof pixels in the enclosure surrounded by the sealing member 3 is placedin a dot matrix arrangement, thereby forming a display area V. Theliquid-crystal drive ICs 4 a and 4 b selectively feed scanning signalsand data signals between opposed electrodes of the plurality of pixels,thereby controlling the alignment of the liquid crystal on a pixel bypixel basis. Light rays passing the liquid crystal is modulated by thealignment control of the liquid crystal, displaying characters andnumerals on the display area V.

[0124]FIG. 12 shows, in enlargement, several of the plurality of pixelsconstituting the display area V in the liquid-crystal device 1. FIG. 13is a cross-sectional view of a single pixel.

[0125] Referring to FIG. 12, the first panel substrate 2 a includes asubstrate 6 a fabricated of glass or plastics, a light reflector 61formed on the interior surface of the substrate 6 a, a color filter 62formed on the light reflector 61, and transparent striped displayelectrodes 63 formed on the color filter 62. As shown in FIG. 13, analignment layer 71 a is formed on the display electrodes 63. Thealignment layer 71 a is subjected to a rubbing process as one of theorientation processes. The display electrodes 63 are fabricated of anconductive transparent material such as ITO (Indium Tin Oxide).

[0126] The second panel substrate 2 b opposed to the first panelsubstrate 2 a includes a substrate 6 b fabricated of glass or plastics,TFDs (Thin Film Diodes) 67 formed on the interior surface of thesubstrate 6 b as an active element functioning as a switching device,and pixel electrodes 69 respectively connected to the TFDs 67. Analignment layer 71 b is formed on the TFDs 67 and the pixel electrodes69 as shown in FIG. 13. The alignment layer 71 b is subjected to arubbing process. The pixel electrodes 69 are fabricated of an conductivetransparent material such as ITO (Indium Tin Oxide).

[0127] The color filter 62 of the first panel substrate 2 a has colorelements 62 a of R (red), G (Green), and B (Blue), or C (Cyan), M(Magenta), and Y (Yellow) in locations facing the pixel electrodes 69 ofthe second panel substrate 2 b, while having a black mask 62 b inlocations not facing the pixel electrodes 69.

[0128] Referring to FIG. 13, the gap, i.e., the cell gap between thefirst panel substrate 2 a and the second panel substrate 2 b is kept toa constant dimension by spherical spacers 54 dispersed on one of thesubstrates. The liquid crystal L is then encapsulated into the cell gap.

[0129] Referring to FIG. 13 and FIG. 14, each TFD 67 includes a firstmetal layer 65, an insulator 66 formed on the surface of the first metallayer 65, and a second metal layer 68 formed on the insulator 66. TheTFDs 67 have a so-called MIM (Metal Insulator Metal) structure, i.e.,the laminated structure of the first metal layer/insulator/second metallayer.

[0130] The first metal layer 65 is fabricated of tantalum only, or atantalum-based alloy. When a tantalum-based alloy is used for the firstmetal layer 65, an element in the group VI to group VIII in the periodictable, such as tungsten, chromium, molybdenum, rhenium, yttrium,lanthanum, or dysprosium, may be added to tantalum as a base material.

[0131] The first metal layer 65 is integrally formed with a first layer79 a of a line wiring 79. The line wirings 79, running in stripesbetween the pixel electrodes 69, work as a scanning line for supplyingthe pixel electrode 69 with a scanning signal, or as a data line forsupplying the pixel electrode 69 with a data signal.

[0132] The insulator 66 is fabricated of tantalum oxide (Ta₂O₃) that isobtained by oxidizing the first metal layer 65 through anodizing. Whenthe first metal layer 65 is anodized, the surface of the first layer 79a of the line wiring 79 is also oxidized. Similarly, a second layer 79 bfabricated of tantalum oxide is thus formed.

[0133] The second metal layer 68 is fabricated of a conductive materialsuch as Cr. The pixel electrode 69 is formed on the substrate 6 b in amanner such that the end portion thereof partly overlaps the secondmetal layer 68. An underlying substrate layer of tantalum oxide may beformed on the surface of the substrate 6 b, before the first metal layer65 and the first layer 79 a of the line wiring 79 are formed. Theunderlying substrate layer is intended to prevent the first metal layer65 from peeling off as a result of a thermal process subsequent to thedeposition of the second metal layer 68, or to prevent an impurity fromdiffusing into the first metal layer 65.

[0134] Referring to FIG. 12, a retardation film 52 a is glued onto theexterior surface of the substrate 6 a. A polarizer 53 a is glued ontothe retardation film 52 a. A retardation film 52 b is glued onto theexterior surface of the substrate 6 b. A polarizer 53 b is glued ontothe retardation film 52 b.

[0135] If an STN (Super Twisted Nematic) liquid crystal is used, forexample, light passing the liquid crystal may be subject to dispersion,causing discoloration to a displayed image. The retardation film 52 aand the retardation film 52 b are optically anisotropic members toeliminate the discoloration, and may be fabricated of a film that isobtained by uniaxially orienting a resin such as polyvinyl alcohol,polyester, polyether amide, or polyethylene.

[0136] The polarizers 53 a and 53 b are optical film elements having thefunction of receiving natural ambient light and outputting a linearlypolarized light ray. The polarizers 53 a and 53 b are produced bysandwiching a polarizer layer between TAC (cellulose triacetate)protective layers. The polarizers 53 a and 53 b are typically arrangedwith the polarization axes thereof different to each other.

[0137] The light reflector 61 is fabricated of a light reflective metalsuch as aluminum. Apertures 49 for transmitting light are formed atlocations corresponding to the pixel electrodes 69 on the second panelsubstrate 2 b, in other words, at locations corresponding to the pixels.

[0138] The display electrodes 63 shown in FIG. 12 extend in the YYdirection as shown in FIG. 15, forming the wirings 24 and the pads 25 inthe overextension 38 as shown in FIG. 16. The pads 25 are electricallyconnected to the output terminals of the liquid-crystal drive IC 4 bmounted on the overextension 38. The wirings 24 have a bilayer structureformed of the transparent conductive layer 70 and the metal layer 72deposited on the transparent conductive layer 70 as shown in FIG. 6(A).As required, the display electrodes 63 also have a bilayer structure ofthe transparent conductive layer 70 and the narrow-width metal layer 72deposited on the transparent conductive layer 70 as shown in FIG. 6(B).

[0139] When the liquid-crystal device 1 thus constructed presents areflective-type display, ambient light entering from the side of aviewer, i.e., from the second panel substrate 2 b into theliquid-crystal display device 1 as shown in FIG. 12, is transmittedthrough the liquid crystal L, reaches the light reflector 61, isreflected therefrom, and returns back into the liquid crystal L. Theorientation of the liquid crystal L is controlled by each pixel by avoltage applied between the pixel electrode 69 and the striped displayelectrode 63, namely, the scanning signal and the data signal. Thereflected light fed to the liquid crystal L is modulated by each pixel,thereby presenting characters and numerals to the viewer.

[0140] On the other hand, when the liquid-crystal device 1 presents atransmissive-type display, the illumination device mounted external tothe first panel substrate 2 a, namely, a back light 59 is lit. Lightfrom the back light 59 is transmitted through the polarizer 53 a, theretardation film 52 a, the substrate 6 a, the apertures 49 of the lightreflector 61, the color filter 62, the display electrodes 63, and thealignment layer 71 a, and then reaches the liquid crystal L. Thereafter,the characters and numerals are then presented in the same way as in thereflective-type display.

[0141] As discussed above, in this embodiment, the wirings 24respectively connected to the display electrodes 63 on the first panelsubstrate 2 a have a bilayer structure of the transparent conductivelayer 70 and the metal layer 72 deposited on the transparent conductivelayer 70. The electrical resistance of the wirings 24 is thus lowercompared with the case in which of the wirings 24 which are formed ofthe transparent conductive layer 70 only. The liquid-crystal device 1thus suffers less from an image quality degradation attributed to avoltage drop through the wirings 24.

[0142] Since there is no need for thickening the transparent conductivelayer 70 to reduce the electrical resistance of the wirings 24, thetransparent conductive layer 70 of the display electrodes 63, which istypically produced concurrently with the transparent conductive layer 70of the wirings 24, does not need too much thickness. The lighttransmittance ratio of the display electrodes 63 becomes higher comparedwith the case in which the electrical resistance of the wirings 24 isreduced only by thickening the transparent conductive layer 70.

[0143] Since the transparent conductive layer 70 used in the displayelectrodes 63 and the wirings 24 is made thinner compared with the casein which the electrical resistance of the wirings 24 is reduced only bythickening the transparent conductive layer 70, the time required toform the counter substrate 2 a, namely, the display device substrate isshortened.

[0144] The present invention may be applied to an active-matrixliquid-crystal device using a three-terminal switching element such as athin-film transistor (TFT). The active-matrix liquid-crystal panel ismanufactured of a pair of substrates, i.e., an element substrate and acounter substrate, and a Twisted-Nematic (TN)-type liquid crystalencapsulated therebetween.

[0145] The element substrate includes scanning lines and data linesintersecting the scanning lines, TFTs, each having the gate thereofconnected to one scanning line and the source thereof connected to onedata line, and conductive transparent pixel electrodes, each connectedto the drain of the TFT. The counter substrate opposed to the elementsubstrate includes wide display electrodes, i.e., common electrodesarranged in stripes and overlapping the horizontally arranged pixelelectrodes on the element substrate.

[0146] The liquid-crystal device AC drives the liquid crystal betweenthe pixel electrode and the display electrode by switching bias voltagelevel applied to the display electrode on a pixel row by pixel rowbasis, i.e., every horizontal scanning period and every verticalscanning period. This drive method is hereinafter referred to as a 1Hbias voltage swing drive method.

[0147] In the active-matrix TFT liquid-crystal device of the fourthembodiment, the wirings on the display device substrate, namely, thecounter substrate, are formed by a laminated structure of a transparentconductive layer and a metal layer. The fourth embodiment thus providesthe same advantage as that of the preceding embodiments.

[0148] The active-matrix TFT liquid-crystal device is now discussedreferring to FIG. 17.

[0149]FIG. 17 shows a circuit arrangement of the liquid-crystal deviceof the fourth embodiment. Arranged in an active matrix area 110 is amatrix of N rows by M columns of pixel TFTs 108. There are also arrangedN scanning lines respectively connected to the gate electrodes of thepixel TFTs and M signal lines (=m×n) respectively connected to thesources of the pixel TFTs. Respectively connected to the M signal linesare analog switch TFTs (20-11, 20-12, . . . , 20-nm).

[0150] The analog switch TFTs are grouped into n blocks, each blockincluding m adjacent analog switch TFTs. Analog switch TFTs (20-11,20-12, . . . , 20-1m) constitute a first block, analog switch TFTs(20-21, 20-22, . . . , 20-2m) constitute a second block, . . . , andanalog switch TFTs (20-1n, 20-n2, . . . , 20-nm) constitute an n-thblock. The gates of the adjacent analog switches (20-11, 20-12, . . . ,20-1m) in the same block are connected together by a first wiring 22-1.The gates of the analog switch TFTs (20-21, 20-22, . . . , 20-2m) areconnected together by a first wiring 22-2, . . . , and the gates of theanalog switch TFTs (20-n1, 20-n2, . . . , 20-nm) are connected togetherby a first wiring 22-n.

[0151] The sources of analog switch TFTs (20-11, 20-21, . . . , 20-n1),which are included different blocks and are not adjacent to each other,are connected together by a second wiring 24-1. Similarly, the sourcesof the analog switch TFTs (20-12, 20-22, . . . , 20-n2) are connectedtogether by a second wiring 24-2, . . . , and the sources of the analogswitch TFTs (20-1m, 20-2m, . . . , 20-nm) are connected together by asecond wiring 24-m.

[0152] The analog switch TFTs are divided into n blocks, each blockincluding m TFTs. By controlling the analog switch TFTs in each block bya control signal for on and off switching, the number of signal lineterminals is reduced to 1/n. For example, M signal line terminals, if noanalog switches are employed, are reduced to m signal line terminals(=M/n). A data driver is connected to m lines of the second wiring 24-1through 24-m. This arrangement reduces the number of data drivers andthe number of terminals, thereby miniaturizing the device and reducingthe cost of the device.

[0153] In the liquid-crystal device of this embodiment, the amplitude ofthe input signal supplied to the sources of the analog switch TFTs20-11, . . . , 20-nm through the second wirings 24-1, . . . , 24-m ispreferably 5 V or lower. This arrangement reduces the amount of shift inthe threshold voltage of the analog switch TFT, thereby assuring thereliability of the device and increasing image quality.

[0154]FIG. 22 plots measurement results of the shift in the thresholdvoltage of the analog switch TFT and operating time. The gate voltage Vgis 20 V, and the load capacitance C of the liquid crystal is set to be atypical load capacitance in a standard liquid crystal panel, namely, ashigh as 10 pF. The operating frequency f is set to be 230 kHz.

[0155] The liquid-crystal device of this embodiment divides the analogswitch TFTs into the n blocks, thereby reducing the number of the datadrivers and the number of the terminals. For example, the number of theanalog switch TFTs is reduced to 1/n, and the time permitted to chargethe pixel electrode is shorter than normal. For this reason, theoperating frequency f is set to be higher. Shift characteristics of thethreshold value of the TFT in response to a rectangular-wave inputsignal having an amplitude of 10 V (Vd=10 V) are represented by curve“G”, and shift characteristics in response to a rectangular-wave inputsignal having an amplitude of 5 V (Vd=5 V) are represented by “H”.

[0156] The threshold voltage of the analog switch TFT is shifted by 1 Vwithin an operating time of 200 hours in response to an input signalamplitude of 10 V. When the input signal has an amplitude of 5 V, theshift amount of the threshold voltage is maintained within 1 V for anoperating time of 10000 hours.

[0157] When the shift amount in the threshold voltage becomes largerthan 1 V, an amount of charge written to each electrode pixel inresponse to data is insufficient. Specifically, the pixel electrodecannot be maintained at a desired voltage, and the contrast of thedisplay is degraded. For example, when the threshold voltage shiftstoward the negative side by 1 V with the threshold voltage of the analogswitch TFT at 1 V or so, the analog switch TFT is put into a depletionmode. Even with the analog switch TFT in an off state, current isleaked, thereby leading to a degradation in display characteristics.

[0158] To increase the reliability of the liquid-crystal device, theshift amount of the threshold voltage must be maintained to within 1 Vwithin at least an operating time of 1000 hours. Preferably, the shiftamount of the threshold voltage is maintained to within 1 V for severalthousand hours. With Vd=10 V, the shift amount becomes larger than 1 Vwithin an operating time of 200 hours, and reaches 2 V within anoperating time of 1000 hours as shown in FIG. 22. This is detrimental toassuring the reliability of the device. Using the input signal with theamplitude thereof not higher than 5 V, the liquid-crystal device of thisembodiment alleviates concentration of electric field at the end portionof the source of the analog switch TFT. In this way, the shift amount ofthe threshold voltage is kept to within 1 V for an operating time of10000 hours or so, and the reliability of the device is assured with asufficient safety margin allowed. Further with the amplitude of theinput signal not higher than 5 V, the difference between penetrationvoltages of the analog switch TFTs is reduced. The direct-currentvoltage applied to the liquid crystal is lowered.

[0159] Referring to FIG. 22, the gate voltage of the analog switch TFTis set to be 20 V in the case Vd=5 V to assure proper comparison withthe case of Vd=10 V. When the amplitude of the input signal is 5 V,namely, Vd=5 V, writing performance is as good as when the gate voltageVg is 20 V with Vd=10 V. In this case, the shift amount of the thresholdvoltage is reduced to be lower than curve “H” shown in FIG. 22, and thereliability of the device is further improved. To further improve thereliability, the input voltage is preferably not higher than 3 V. Curve“I” shown in FIG. 22 represents shift characteristics in response to theinput voltage of 5 V at an operating frequency of 32 kHz.

[0160] In the liquid-crystal device of this embodiment, the pixel TFTand the analog switch TFT, fabricated of polycrystalline silicon ormonocrystalline silicon, are integrally formed on a glass substrate.Display characteristics will be degraded if charging and discharging ofa pixel electrode are not completed within a predetermined duration oftime when an input signal is applied to an analog switch TFT. For thisreason, the on resistance of the analog switch TFT needs to be reduced.When the analog switch TFTs are divided into the n blocks to reduce thenumber of the data drivers, the requirement for the reduction of the onresistance is even more rigorous. Amorphous silicon TFTs have anextremely low mobility. For their on resistance characteristics, theamorphous silicon TFTs cannot be used for an analog switch TFT even ifit can be used for a pixel TFT.

[0161] In this embodiment, the pixel TFT and the analog switch TFT arefabricated of polycristal silicon or monocrystal silicon, having amobility substantially higher than that of the amorphous silicon TFT.This arrangement allows the pixel TFT and the analog switch TFT to beintegrally formed on the glass substrate. With the pixel TFT and theanalog switch TFT integrally formed on the glass substrate, externaldimensions of the liquid-crystal device are miniaturized and the costthereof is reduced.

[0162]FIG. 18 illustrates the manufacturing method for integrallyforming the pixel TFT and the analog switch TFT and the structure of theTFTs. An underlying insulator 132 for preventing impurities fromdiffusing from a glass substrate 130 is deposited on the glass substrate130. A polycrystalline silicon thin layer 134 is then deposited on theunderlying insulator 132. The crystallinity of the polycrystallinesilicon thin layer 134 must be improved to increase mobility in responseto the field effect. To this end, the polycrystalline silicon thin filmis recrystallized using a laser anneal or solid phase epitaxy, orpolycrystalline silicon resulting from recrystallizing an amorphoussilicon film is used. The polycrystalline silicon thin layer 134 ispatterned in islands, and a gate insulator 136 is then depositedthereon.

[0163] A gate electrode 138 is formed of a metal, for example. Thedoping with an impurity such as phosphorus ions is performed over theentire surface of the laminate. An interlayer insulator (SiO₂) 140 isthen formed. A metal thin layer 142, of aluminum (Al) for example, isdeposited for signal lines. A pixel electrode 144 is fabricated of atransparent conductive layer such as of ITO. A passivation layer 146 isthen formed. A substrate having the pixel TFT integrated with the analogswitch TFT thus results. The substrate is then subjected to an alignmentprocess. A counter substrate 135, which has been similarly subjected toan alignment process, is arranged to be opposed the element substratewith a gap of several μm maintained therebetween. The liquid crystal Lis then encapsulated between the substrates. A liquid-crystal device isthus produced.

[0164] The counter substrate 135 has a display electrode 22 formed onthe surface facing the liquid crystal L as shown in FIG. 3. Terminalsfrom external circuits are connected to the pads 25 of the wiring 24 towhich the display electrodes 22 extend. The wirings 24 has a bilayerstructure of the transparent conductive layer 70 and the metal layer 72as shown in FIG. 6(A). As required, the display electrodes 22 also havea bilayer structure of the wide-width transparent conductive layer 70and the narrow-width metal layer 72 deposited on the transparentconductive layer 70 as shown in FIG. 6(B).

[0165] The liquid-crystal device 101 shown in FIG. 17 may be designed inan external configuration shown in FIG. 19, for example. Referring toFIG. 19, a display area, i.e., an active matrix area 160, is shownenclosed by a broken line. The liquid crystal material is interposedbetween a color filter substrate 162 and a TFT substrate 164. The analogswitch TFTs and their associated wirings are arranged on an area 166.

[0166] A data driver 170 is mounted using a TAB (Tape Automated Bonding)tape 168. A data driver 172 and a scanning driver 174 are similarlymounted using the TAB tape 168.

[0167] A circuit board 176 bears wirings and capacitors for feedingsignals to the data drivers 170, and 172, and the scanning driver 174.As required, a control circuit for controlling the data drivers and thescanning driver is arranged on the circuit board 176.

[0168] In the embodiment shown in FIG. 19, half of the analog switchTFTs is mounted on the top side of the active matrix area 160, while theother half of the analog switch TFTs is mounted on the underside of theactive matrix area 160. The M signal lines shown in FIG. 17 are thusinterdigitally arranged from the top side and the bottom side of theactive matrix area 160. The data drivers and the scanning driver aremounted on the same sides of the color filter substrate 162 and the TFTsubstrate 164 forming a liquid-crystal panel. In this way, the dimensionL3 of the liquid-crystal device of this embodiment is substantiallyreduced. The liquid-crystal device suitably finds applications in mobiletelephones, mobile electronic terminals, etc.

[0169] As discussed above, the amplitude of the input signal to thesource of the analog switch TFT is preferably not higher than 5 V toproperly control the shift amount of the threshold voltage of the analogswitch TFT in the liquid-crystal device 101 of this embodiment. However,the following problem can arise in the standard drive method.

[0170]FIG. 21 shows the standard drive method using a field polarityreversal. Since the liquid crystal needs to be driven from analternating current, a signal Vs applied to the signal line is reversedwith respect to a predetermined voltage Vc in polarity everypredetermined period. Referring to FIG. 21, the voltage Vs swings in alarge amplitude. Since a standard TN liquid crystal needs a voltage of±5 V, the voltage Vs has an amplitude of 10 V or so. A voltage Vcomapplied to the counter electrode is lower than the central voltage Vc ofthe voltage Vs by ΔV to compensate for a penetration voltage that occurswhen the pixel TFT is in an off state. Here, the condition of averageΔV=Vc−Vcom holds.

[0171] Referring to a drive voltage waveform diagram shown in FIG. 21,the amplitude of the input signal to the analog switch TFT needs to beas large as 10 V. The amplitude of the input signal to the analog switchTFT also needs to be large. For this reason, the input signal cannot bereduced to an amplitude smaller than 5 V. Accordingly, the presentembodiment reverses the polarity of the voltage applied to the counterelectrode relative to the input signal every horizontal scanning periodas shown in FIG. 20. (This drive method is called a 1H bias voltageswing drive method.)

[0172] Referring to FIG. 21, the polarity of the voltage Vs is reversedwith respect to the voltage Vc every field. In the 1H bias voltage swingdrive method, the polarity of the Vcom is reversed every horizontalscanning period. This eliminates the need for the polarity reversal ofthe voltage Vs. The amplitude of the Vs is thus reduced. For thisreason, the input signal to the analog switch TFT can be set to besmaller than 5 V while the display quality of the device is maintained.Since the operating voltage of the data drivers is lowered, the devicecan be manufactured on a manufacturing process supporting 5 V withstandvoltage specifications. The data drivers are thus miniaturized, andreduced in power consumption and costs.

[0173] The 1H bias voltage swing drive method satisfies both thereliability requirement to the analog switch TFT and low operatingvoltage requirement of the data drivers. Referring to FIG. 20, thecondition of average ΔV=average Vs−average Vcom holds to control theadverse effect of penetration voltage.

[0174] In this embodiment, as discussed above, the striped displayelectrodes 22 shown in FIG. 3 are formed on the counter substrate 135shown in FIG. 18. The wirings 24 leading to the display electrodes 22have a laminated structure of the transparent conductive layer 70 andthe metal layer 72 as shown in FIG. 6(A). The electrical resistance ofthe wiring 24 is reduced to be lower than when the wirings 24 arefabricated of the transparent conductive layer 70 only. Theliquid-crystal device thus suffers less from an image qualitydegradation attributed to a voltage drop through the wirings 24.

[0175] Since there is no need for thickening the transparent conductivelayer 70 to reduce the electrical resistance of the wirings 24, thetransparent conductive layer 70 of the display electrodes 63, which istypically produced concurrently with the transparent conductive layer 70of the wirings 24, does not need too much thickness. The lighttransmittance ratio of the display electrodes 63 becomes higher comparedwith the case in which the electrical resistance of the wirings 24 isreduced only by thickening the transparent conductive layer 70.

[0176] Since the transparent conductive layer 70 used in the displayelectrodes 63 and the wirings 24 is made thinner compared with the casein which the electrical resistance of the wirings 24 is reduced only bythickening the transparent conductive layer 70, the time required toform the counter substrate 2 a, namely, the display device substrate isshortened.

[0177] FIGS. 8(A), 8(B), and 8(C) show embodiments of electronicequipment which incorporates one of the liquid-crystal device 10 shownin FIG. 1, the liquid-crystal device 1 shown in FIG. 15, and theliquid-crystal display device 101 shown in FIG. 17. FIG. 8(A) shows amobile telephone 88 having the liquid-crystal device 10 or the like onthe upper portion thereof. FIG. 8(B) shows a wristwatch 92 having theliquid-crystal device 10 or the like as a display section thereof. FIG.8(C) shows a mobile information terminal 96 having the liquid-crystaldevice 10 or the like as the display section thereof and an inputsection 98.

[0178] Besides the liquid-crystal device 10, each of the aboveelectronic equipment includes a diversity of circuits including adisplay information output source 86, a display information processor87, a clock generator 89, etc., and a display signal generator 93including a power source circuit 91 for supplying these circuits withpower. The mobile information terminal 96 shown in FIG. 8(C) displays,on the display section thereof, an image generated in response to thesupply of display signals produced by the display signal generator 93based on input information from the input section 98.

[0179] The electronic equipment incorporating one of the liquid-crystaldevices 10 and the like of the above embodiments is not limited to themobile telephone, the wristwatch, and the mobile information terminal.The electronic equipment may include a notebook computer, an electronicnotebook, a pager, a tabletop calculator, a POS terminal, an IC card, amini-disc player, etc.

[0180] The preferred embodiments of the present invention have beendiscussed. The present invention is not limited to these embodiments. Avariety of changes and modifications of these embodiments is possiblewithin the scope of the appended claims.

[0181] In the above embodiments, the transparent conductive layer isfabricated of ITO, and the metal layer is fabricated of aluminum. Aslong as a material forming the transparent conductive layer has asufficiently high light transmittance and a sufficient conductivity, anymaterial is acceptable. For example, tin oxide or silver may beemployed. The transparent conductive layer may be a transflective layerpartly reflective and partly transmissive. As long as a material formingthe metal layer has a sufficient conductivity, any material isacceptable. For example, chromium, copper, silver, or gold may beacceptable.

[0182] The liquid-crystal panel discussed above may include a colorfilter on the interior surface of one of the substrates, thereby makinga color display device. The color filter is preferably formed beneaththe display electrode.

[0183] In each of the above embodiments, an STN liquid crystal is usedfor the liquid-crystal panel. The liquid-crystal panel is not limited tothis. Employed is any of a variety of liquid-crystal panels of TN(Twisted Nematic) type, guest-host type, phase transition type, bistableTN (Twisted Nematic) type, and ferroelectric type. The display electrodeis not limited to a striped configuration. The display electrode mayhave a character such as an icon.

[0184] A transmissive-type liquid-crystal device is shown in theembodiment in FIG. 1. The present invention is applicable to areflective-type display device. Such a liquid-crystal device employs areflector behind the substrate or a reflective electrode as one of thedisplay electrode, instead of a back light unit.

[0185] The present invention is not limited to any of the aboveembodiments. A variety of changes, modifications and equivalents arepossible within the scope of the present invention.

[0186] As discussed above, the present invention includes a wiringhaving a laminated structure of a transparent conductive layer and ametal layer. The electrical resistance of the wiring is lower than whenthe wiring is constructed of the transparent conductive layer only. Aliquid-crystal device incorporating the display device substrate of thisinvention suffers less from image quality degradation attributed to avoltage drop across the wiring.

[0187] Since there is no need for thickening the transparent conductivelayer to reduce the electrical resistance of the wirings, thetransparent conductive layer of the display electrodes, which istypically produced concurrently with the transparent conductive layer ofthe wirings, does not need too much thickness. The light transmittanceratio of the display electrodes becomes higher compared with the case inwhich the electrical resistance of the wirings is reduced only bythickening the transparent conductive layer.

[0188] Since the transparent conductive layer used in the displayelectrodes and the wirings is made thinner compared with the case inwhich the electrical resistance of the wirings is reduced only bythickening the transparent conductive layer, the time required to formthe counter substrate, namely, the display device substrate isshortened.

What is claimed is:
 1. A display device substrate comprising a pluralityof display electrodes, and a plurality of wirings for applyong theplurality of display electrodes with a voltage, wherein the plurality ofwirings comprises a laminated structure composed of a transparentconductive layer formed of the same layer as that of the displayelectrodes, and a metal layer fabricated of a metal having an electricalresistance lower than that of the transparent conductive layer.
 2. Thedisplay device substrate according to claim 1, wherein the displayelectrode comprises a laminated structure composed of a transparentconductive layer, and a metal layer fabricated of a metal having anelectrical resistance lower than that of the transparent conductivelayer.
 3. The display device substrate according to claim 2, wherein themetal layer in the display electrode is narrower in width than thetransparent conductive layer.
 4. The display device substrate accordingto claim 1, wherein the display electrode comprises the laminatedstructure of the transparent conductive layer and the metal layer, andwherein the metal layer has an aperture partially opened in thelaminated structure.
 5. The display device substrate according to claim1, wherein the wirings are routed from the ends of the respectivedisplay electrodes along the peripheral portion of the display devicesubstrate.
 6. A liquid-crystal device encapsulating a liquid crystalbetween a pair of substrates, the device comprising the display devicesubstrate according to claim 1 as at least one of the pair ofsubstrates.
 7. A liquid-crystal device comprising: the display devicesubstrate according to claim 4; a counter substrate opposed to thedisplay device substrate; and a liquid-crystal layer encapsulatedbetween the display device substrate and the counter substrate, whereinthe liquid-crystal device has a transmissive display function using theaperture of the metal layer as a light transmissive section and areflective display function using the region of the metal layer as alight reflective section.
 8. Electronic equipment comprising: theliquid-crystal device according to claim 7 as display means.
 9. Amanufacturing method for manufacturing the display device substrateaccording to claim 1, the manufacturing method comprising: a transparentconductive layer fabrication step for fabricating a transparentconductive layer on the display device substrate; a metal layerdepositing step for depositing a metal layer on the transparentconductive layer; and an etching step for concurrently etching thetransparent conductive layer and the metal layer.
 10. The manufacturingmethod for manufacturing the display device substrate according to claim1, the manufacturing method comprising: a transparent conductive layerfabrication step for fabricating a transparent conductive layer on thedisplay device substrate; a metal layer depositing step for depositing ametal layer on the transparent conductive layer; a first etching stepfor concurrently etching the transparent conductive layer and the metallayer using a first photoresist film; and a second etching step foretching only the metal layer using a second photoresist film, whereinthe second photoresist film having a predetermined pattern is created bysubjecting the first photoresist film to exposure and developmentprocesses.
 11. The manufacturing method for manufacturing a displaydevice substrate according to claim 10, wherein the metal layer in thedisplay electrode is etched through the second etching step so that themetal layer is left on only the edge portion of the transparentconductive layer.
 12. The manufacturing method for manufacturing adisplay device substrate according to claim 10, wherein the metal layerin the display electrode is etched through the second etching step sothat the metal layer has an aperture on the transparent conductivelayer.
 13. A liquid-crystal device comprising a pair of display devicesubstrates, and a liquid crystal encapsulated between the display devicesubstrates, wherein one of the pair of display device substratescomprises a plurality of pixel electrodes, and a plurality oftwo-terminal-type switching elements, each connected to the respectivepixel electrode, the other of the pair of display device substratescomprises a plurality of display electrodes arranged in stripes to beopposed to the plurality of pixel electrodes, and wirings respectivelyconnected to the display electrodes, the plurality of display electrodescomprises a transparent conductive layer, and the wirings comprise atransparent conductive layer formed of the same layer as that of thedisplay electrodes, and a metal layer fabricated of a metal having anelectrical resistance lower than that of the transparent conductivelayer.
 14. A liquid-crystal device comprising a pair of display devicesubstrates, and a liquid crystal encapsulated between the display devicesubstrates, wherein one of the pair of display device substratescomprises a plurality of pixel electrodes, and a plurality ofthree-terminal-type switching elements, each connected to the respectivepixel electrode, the other of the pair of display device substratescomprises a plurality of display electrodes arranged in stripes to beopposed to the plurality of pixel electrodes, and wirings respectivelyconnected to the display electrodes, the plurality of display electrodescomprises a transparent conductive layer, and the wirings comprise atransparent conductive layer formed of the same layer as that of thedisplay electrodes, and a metal layer fabricated of a metal having anelectrical resistance lower than that of the electrically transparentlayer.